In steelmaking, energy-saving considerations often dictate the use of insulated covers and similar structures over ladles and over molten metal and slag-receiving vessels. See, for example, U.S. Pat. No. 5,176,876, which issued on Jan. 5, 1993 in the name of Joseph S. Simko, Jr. and which is assigned to the same assignee as is the present invention. Because the vessels themselves are often lined with rigid ceramic insulation which would suffer from thermal shock upon the discharge of molten metal or slag into it, the custom has long existed to heat such empty vessels prior to the discharge of molten metal into them. In some ladle covers and like structures, openings have been provided for the insertion of gas burners through the cover so that the cover need not be removed to insert the burner. Because the area immediately around these openings is subject to greater wear and deterioration, replaceable burner blocks have been secured at these openings and these blocks have been made to be relatively easily replaced. These known prior art burner blocks have been made of cast refractory material. Such blocks have proven to be relatively expensive, prone to breakage in the tough environment of an active steel mill, and even when not breaking have had to be replaced at frequent intervals.
There thus exists a need for a burner block which is economical to use, lasts a long time in use, and/or is of rugged construction and not prone to fracture easily.